1. Field of the Invention
The present invention relates to a cellular phone terminal with which the reception frequency is corrected on the basis of a reference signal transmitted from a base station, and to a frequency correcting method for the cellular phone terminal.
2. Description of the Related Art
TCXO (Temperature-Compensated Crystal Oscillator) which can generate a high-precision frequency having an error of ±3 ppm (volume parts per million), for example, has been hitherto used as an oscillator to receive/transmit radio signals with high precision in a cellular phone terminal.
In connection with recent widespread use of cellular phone terminals, it has been required to reduce the cost of the cellular phone terminals. Particularly, it has been strongly required to reduce the cost of a radio portion having the highest maturity among the parts constituting each cellular phone terminal. TCXO occupies a relatively large cost in the radio portion and thus it has been required to get an inexpensive crystal oscillator as a replacement for TCXO. However, such an inexpensive crystal oscillation circuit has a disadvantage that it has a large frequency error of ±50 ppm or more and thus it is unfavorable for the cellular phone terminals which receive/transmit radio signals with high precision.